Equation Balancer Help

You can enter (free-formatted) any kind of unbalanced chemical equation, and the program will instantly balance it for you. Equations can be oxidation-reduction (redox), organic, half-reactions... almost any chemical equation.

For each balanced equation, the molar masses of all reactants and products are displayed. You may optionally enter the mass of any one item involved in a given reaction, and all of the other values will be calculated for you. This is very useful for solving problems such as: determine the mass of NaCl which is produced when 20 grams of Na reacts with Cl2.

Equations may be entered pretty much free-form. It's fairly intuitive. For example: CaO + P4O10 = Ca3(PO4)2 . Compounds may be entered as they are normally written, no matter how complex. You can enter HOOC(CH2)4COOH without having to combine elements.

Spaces are optional. You may add spaces and carriage returns wherever you want, except within a two-letter element's symbol or in the middle of a number or a charge specification. Even if your input does not contain any spaces, the balanced equation will have just enough spaces added to make for an eye-pleasing format.

You do not have to capitalize elements -- the program knows which letter combinations are elements. Thus, you can enter sodium's symbol as either Na or na. This means, however, that if you don't capitalize, you must be careful when putting elements next to each other. For example, co will be interpreted as Co: cobalt. If you want to have carbon monoxide, you could type any of the following: CO or c  o or cO or c1o1 (among others). If the program cannot balance an equation, check the reformatted version of your input which is printed with the error message. It shows what elements the program thinks you're trying to use, and elements are printed in alternating colors to help you find capitalization typos. It will also suggest checking any specific capitalization situations which could potentially be ambiguous; if you entered the correct symbols, you should, of course, just ignore the suggestion.

O and Zero
Be careful when entering O that you don't accidentally enter a zero instead. Check for things like H20 when you meant H2O. To help you discover this surprisingly common problem, if you have an error, any zeros in your unbalanced equation will be highlighted, including any correct ones.

To specify a charge, enclose it in your choice of brackets: <...> or [..] or {..} . Again, the charge is very free-form. An aluminum ion could be entered as: Al<+++> or al{+3} or Al[3+] or even something odd such as al<+++] . Any combination of styles enclosed in angle brackets, curly braces, and square brackets is acceptable. Note that parentheses () may not be used for this. In some cases, the right brackets may even be omitted where it would not be ambiguous. If the charge starts with -, both brackets are optional. Example: a sulfate ion may be entered as so4-2 and hydroxide could be entered as OH-. A left bracket is always required for a positive charge, since + may be used both as a charge and as a compound separator.

No spaces or carriage returns are allowed anywhere within a charge specification.

Half-reactions may also be balanced. To specify an electron, use: e-
If your input contains a positive or a negative ion but not both, electrons will be added to your input in an attempt to balance the charge.

Phase and Arrows
Note -- sometimes you will see the phase of a reactant or product specified in an unbalanced equation. For example, (s) for solid or (g) for gas. The phase should never be entered into the equation balancer. Also, equations are often depicted with the reactants separated from the products by a single or double arrow. To enter an equation on this site, use an equals sign instead of an arrow. Example: to balance the equation C (s) + O2 (g)  -->  CO2 (g) you should enter: C + O2 = CO2.

The formatting of the balanced equation will be based on your formatting of the unbalanced equation. If you put something on the wrong side of the unbalanced equation, it will be moved to the correct side.

If you enter a coefficient in front of any reactant or product, it will be ignored. The balanced equation will always have the smallest integer coefficients possible.

Acidic and Basic Solutions
If you specify a reaction in acidic or basic solution, you don't have to include the H+, OH-, or H2O -- they'll be added automatically as needed. Omitting them will allow you to easily see the results in both acidic and basic solutions. For example, enter your unbalanced equation without H+ or OH-, click on Acidic solution, then submit. When you're shown the balanced equation, click on Basic solution and resubmit, without having to change anything in the unbalanced equation.

Molar Mass Example
Determine the mass of NaCl which is produced when 20 grams of Na reacts with Cl2.

First, enter the unbalanced equation: Na + Cl2 = NaCl . Make sure the Display mass information box is checked, then click on Balance it. You'll see the balanced equation Na + Cl2 = NaCl and a table containing the molar masses of Na, Cl2, and NaCl. Enter 20 next to the Na and click on Calculate. You will see that 50.84241 grams of NaCl are produced from 20 grams of Na.

Note that this assumes there is sufficient Cl2 present for all of the Na to completely react. Also note that if you are checking your answers to a homework assignment, your instructor may have provided a table of atomic masses which is rounded off to different decimal places, or which contains values for elements which are present in different mixtures of isotopes than the table which is used on this site. Thus, your answers may differ by several decimal places.

If you enter more than one mass, the calculations will be based on the first one you entered.

You must enter complete, unbalanced equations, using the proper chemical symbols (not names). If you specify acidic or basic solutions, H2O and H+ or OH- will be added automatically as needed, but this site will not attempt to determine any other missing items. In particular, you may not supply just the reactants -- this site will not figure out the products of the reaction.

Please note that this site generally cannot balance equations containing compounds depicted with a Chemical Period. In chemical notation, this is used to separate two components of a compound; for example, to separate the water of hydration from the rest of a compound. This is denoted in any of several ways, including those in the following examples: CaCl2 · 6H2O or CaCl2 * 6H2O. There is no way for you to enter such a compound in that form on this site.

This site is also unable to balance equations which have multiple correct ways of being balanced. For example, the unbalanced equation
I4O9 = I2O6 + I2 + O2 can be balanced in four different ways. That equation can not be balanced on this site.

Sometimes the Equation Balancer is unable to balance equations which are the sum of other equations, or when the reactants are the same as (or occasionally if they are too similar to) the products, or if extraneous reactants or products have been entered.

Guest Access and Sample Equations
To see how easy it is to enter equations in a free-formatted manner, with different ways of capitalizing, spacing, and entering charges, you may try some sample equations. These samples can be balanced by any user. Guest users have their access limited to three total compounds, and all of the samples fit this profile. Remember, though, that premium access users can enter equations with a virtually unlimited number of reactants and products.

Nanday home